Method and apparatus for removing hair roots from pork bellies



J y 0 w. w. LEHMAN ETAL 3,520,011

METHOD AND APPARATUS FOR REMOVINGi HAIR ROOTS FROM PORK BELLIES FiledMay 27, 1968 I 2 Sheets-Sheet 1 WILLIS w. LEHMAN ELWOOD A. OLSON LEO E.O'NEAL' INVENTORS BY WJ M AGENT y 1970 w. WQLEHMAN'" ET AL 3,520,011

METHOD AND APPARATUS FOR REMOVIN G HAIR ROOTS FROM PORK BELLIES FiledMay 27. 1968 z Sheets-Sheet 2 FIG 3 WILLIS w. LEHMAN ELWOOD A. OLSON LEOE. O'NEAL INVENTORS AGENT United States Patent 3,520,011 METHOD ANDAPPARATUS FOR REMOVING HAIR ROOTS FROM PORK BELLIES Willis W. Lehman,Glenville, and Elwood A. Olson and Leo E. ONeal, Albert Lea, Minn.,assignors to Wilson and C0., Inc., Chicago, llll., a corporation ofDelaware Filed May 27, 1968, Ser. No. 732,177 Int. Cl. A22b /08; C14b17/00 US. Cl. 171 7 Claims ABSTRACT OF THE DISCLOSURE Disclosed are amethod and apparatus for removing hair roots from skinned pork belliesby impinging upon the bellies a spray of hot water under pressure.

FIELD OF THE INVENTION This invention relates to butchering, and moreparticularly to a method and apparatus for removing hair roots fromskinned pork bellies.

DESCRIPTION OF PRIOR ART In the commercial butchering of hogs, thecarcasses are scalded and passed through a dehairing machine wheresubstantially all the hair is removed from the surface of the hogs skinby the beating action of steel-tipped rubber paddles. This mechanicalprocess may be supplemented with singeing and manual shaving with aknife. However effective these processes may be in removing the hogshair from the surface of the skin, some hair connected to hair rootsremains embedded beneath the skin. Previously, this problem wasparticularly prevalent in the so-called hardhair season, principallyJuly through October, during which time the hogs develop a new coat ofhair, the new hair being more difiicult to remove. Recently, becausepigs are farrowed the year round, the hard-hair season encompasses theentire calendar year. Since the hair roots occur just beneath theepidermis or outer skin layer of the hog, their presence is not aparticular problem in the preparation of the hams and loins because asubstantial amount of fat is removed from these parts of the hog alongwith the outer skin layer. However, the removal of hair roots fromskinned pork bellies has been a difficult and costly problem in the hogbutchering industry. It is desired that as much of the belly be savedfor curing as possible. Consequently, the bellies are skinned so that,in general, only the epidermis is removed, exposing the pebble fat ordermis of the pork belly, which contains the hair roots. To satisfy therequirements of the US. Department of Agriculture and to produce asaleable prodnot, these hair roots must be removed. In the past, theonly method known for removing hair roots from pork bellies has beenhand scraping with a knife or other sharp instrument adapted forscraping. This method sulfers from two serious disadvantages. First,removal by scraping requires that some fat be removed along with thehair roots. This fat containing the hair roots is waste, to the extentthat it must be sold as inedible fat rather than bacon. Second, scrapingis arduous and time-consuming work requiring additional laborers on theproduction line, the number of which vary during the year, dependingupon the severity of the hair root problem. Thus, the need for removalof the hair roots has caused a serious restriction on productivity.

In accordance with this invention, hair roots are removed from skinnedpork bellies by impinging upon the bellies a spray of hot water underpressure. The bellies are positioned on a mesh conveyor belt and pass bya spray head at least as wide as the belly which directs jets of hotwater onto the surface of the bellies, effectively 3,520,011 PatentedJuly 14, 1970 washing the hair roots from the belly. To contain the hotwater spray, the spray head and conveyor are provided with a cover whichis vented to carry off condensed water vapor or steam.

Accordingly, it is an object of the present invention to provide amethod and apparatus for rapidly and economically removing hair rootsfrom skinned pork bellies.

Another object is to provide a method for removing hair roots fromskinned pork bellies which eliminates waste.

A further object is to provide a method for removing hair roots fromskinned pork bellies which requires less labor and increasesproductivity.

Other objects and advantages will be apparent from the specification andclaims and from the accompanying drawing illustrative of the invention.

In the drawing:

FIG. 1 is a perspective view of an embodiment of apparatus according tothe invention comprising a mesh conveyor belt, a spray head locatedthereon, and a cover disposed over the spray head and a portion of thebelt;

FIG. 2 depicts the apparatus shown in FIG. 1 and further provided withswitching means and means for adjusting the spray head in response tovariations in thickness of the pork bellies;

FIG. 2a is a schematic view of one arrangement of the water supplycontrol;

FIG. 3 is a side view illustrating the operation of the spray head ofthe apparatus shown in FIG. 2;

FIG. 4 is a view showing water from one embodiment of the spray headstriking a pork belly;

FIG. 5 is a cross-sectional view of the spray head shown in FIG. 4;

FIG. 6 is a view showing water from another embodiment of the spray headstriking a pork belly; and

FIG. 7 is a cross-sectional view of the spray head shown in FIG. 6.

Referring now to FIG. 1, the apparatus of the invention comprises aspray head 1 for directing hot water under pressure onto pork bellies 2to be cleaned. The apparatus further comprises an endless conveyor belt3 supported by frame 4 and located beneath the spray head for conveyingthe skinned pork bellies to and away from the spray head. A mesh belt ispreferred because it provides a stable support for the pork bellies aswell as ensuring that the pork bellies remain in a fixed position whenstruck by the spray. If a non-perforated belt were used, it wouldaccumulate water, thus causing the bellies to float and slide about. Themesh belt provides the further advantage of permitting the water to passdirectly therethrough and out a drain. Motive power is imparted to theendless, mesh conveyor belt 3 by gears 5, driven by a suitable motor,not shown.

Because of the high pressure and temperature of the spray, it ispreferable to provide a suitable cover for the spray apparatus '1. Inthe embodiment shown, the cover is essentially a rectangular, bottomlessenclosure the same width as the frame 4 and having a top 6 andpositioned over the spray head 1 and mesh belt 3 so as to cover thespray head and at least the pork belly being sprayed. Swinging doors 7and 8 are located in the sides of the enclosure perpendicular to thedirection of travel of the belt, extend across the width of the belt,and permit the pork belly to pass into and out of the enclosure, butotherwise remain closed to retain the Water inside the enclosure. Tofurther prevent the escape of the spray from the enclosure, baffles 9and 10 are mounted inside the enclosure and parallel to those sideswhich have doors 7 and 8. The bafiles are as wide as the inside of theenclosure and extend from the top 6 to the belt 3. The sections 11 and12 of each bafile adjacent the belt are hinged to permit the pork bellyto proceed along with the belt, but otherwise remain perpendicular tothe belt to promote retention of the spray within the enclosure. Thecover has a vent or chimney 13- on the top 6 to remove the condensedwater vapor or steam which forms during the use of the device.

The apparatus further includes means (not shown) including a pump forsupplying hot water under pressure through water supply line 14 to thespray head 1. The apparatus is also provided with gauges 1 and 16 in thewater supply line 14 near the spray head for measuring the waterpressure and temperature respectively. In the example shown, the sprayhead is mounted at a fixed distance above the belt by means of, forexample, a first, upstanding member 17 footed on one side of the frameand a second, upstanding member 1 8 similarly footed on the oppositeside of the frame, the spray head being attached to the upstandingmembers 17 and 18 by suitable clamps, such as 19. One skilled in the artwill readily perceive modes of rendering the height of the spray headabove the belt adjustable at will, if so desired. The spray head is alsorotatable with respect to its mounts.

Since frequently not all pork bellies contain hair roots after skinning,it may be desirable to expose to the water sprays only those bellieswhich do require removal of hair roots, thus conserving water. Inaccordance with the embodiment shown in FIG. 2, selective control isachieved by installing a triggering device 20 along one side of theenclosure parallel to the directional of travel of the belt before thespray head 1, and near enough to the belt 3 to touch a pork belly ofminimum thickness. The triggering device extends a short distance fromthe side of the cover so that contact with a passing pork bellyactivates the device, thus turning on the water. The

triggering device is arranged so that, after the belly has passed thespray head, the water flow is shut off. Those pork bellies not requiringhair root removal are positioned on the conveyor belt, by an operator,toward the side opposite the triggering device so they do not come incontact with the trigger, thus leaving the supply of water shut off.Through this method, considerable savings in Water usage can beachieved.

While many means for controlling the water supply will be apparent tothose skilled in the art, one suitable arrangement is depictedschematically in FIG. 2a. The triggering device 20 is affixed in thecover all by flexible mounting means 31, and is mechanically connectedto a micro-switch 3-2 which activates a solenoid 33 controlling athree-way valve 34 in the water supply line from the pumps to the sprayhead. When no pork belly is in contact with the triggering device 20,the micro-switch 32 is open and the valve 34 reciroulates the water backto the pump. When a pork belly touches the triggering device, themicro-switch is closed, thus activating the solenoid 3-3, which causesthe valve to direct water from the pump to the spray head. After thepork belly has passed by the triggering device, the micro-switch 32returns to its normally open position, which deactivates the solenoidand shuts off the supply of water to the spray head.

The apparatus preferably further comprises means for adjusting the sprayhead to respond to variations in thickness of the pork bellies. In theembodiment shown in FIG. 2, a roller 21 is fixedly mounted in parallel,spaced relation in front of the spray head by connecting rods 22. Thenozzle portion of the spray head to which the connecting rods attach isfreely rotatable with respect to the ends of the spray head, which isfirmly attached to the frame 4, as described above. As more fullyillustrated in FIG. 3, as pork of increasing thickness is encountered bythe roller 21, the nozzles are turned upward or in a clockwise directionso that the distance from the nozzles to the surface of the pork bellyremains substantially the same. As is apparent from FIG. 3, as theroller 21 is raised, the angle of the spray to the belly decreasesslightly. Accordingly, the length of the connecting rods 22, whichgenerally determines the angle of the spray, is chosen so as to providethe optimum angle for the belly of median thickness.

Preferably, the nozzles of the spray head are of the type which producea fine spray and thus use a relatively low volume of water. In theembodiment shown in FIG. 4, the spray head comprises thirteen nozzles41, each having a 0.062 inch diameter orifice and arranged in a rowalong a 15 inch section of a 1% inch internal diameter water pipe 42.The particular nozzles described each produce a fan spray 43 having awidth of 25 degrees. The mounting of a nozzle 41 in the pipe 4-2 isfurther illustrated in FIG. 5.

Preferably, interference of the sprays with each other, which reducesthe strength of their impact upon the pork belly, is avoided. Inaccordance with the particular arrangement shown in FIG. 4, the fansoverlap only slightly to produce a continuous section of spray at thepoint of contact with the pork belly 44. If the nozzles are not disposedin the same vertical plane, however, for example if they are staggered,the sprays can overlap without interfering.

In an alternative embodiment of the spray head shown in FIG. 6, thewater pipe 61 contains a narrow slit or aperture forming an elongatenozzle 62 which produces a continuous, thin sheet of spray 63 whichstrikes the pork belly 64 uniformly. FIG. 7 is across-sectional view ofthe water pipe 61 showing the slit in greater detail. The elongatenozzle may be formed in a section of the pipe, for example, by cutting aslit or aperture 71 in the pipe and inserting in the slit 71 a nozzle62.

In operating the device of the invention, the temperature of the waterused should be about to F. It has been observed that, at temperaturesbelow 140 F., the effectiveness of the device is increased as the watertemperature is increased. It is believed that a water temperature of atleast 130 F. is necessary to release the hair follicle, or root, fromthe fat in which it is imbedded. On the other hand, water temperaturessubstantially in excess of 140 F. have been observed to detrimentallyaffect the fat.

The angle of the spray through the mesh belt should be 25-45 degreesfrom the perpendicular, measured from the surface of the mesh belt andtoward the approaching pork belly. The optimum angle is about 35degrees. The spray head is located a few inches from the mesh belt, forexample 4 to 5 inches. Pork bellies can vary in thickness form 1 /2inches to as much as 4 inches. Accordingly, it will be apreciated thatthe distance from the top surface of the pork belly to the spray headwill vary between 1 and 3 /2 inches, in proportion to the thickness ofthe pork belly. If it is desired to optimize the distance from the sprayhead to the top surface of the pork belly, the pork bellies are eithergraded according to thickness or the apparatus is provided with meansfor adjusting the spray head in response to the thickness of the pork'belly to maintain the optimum distance, as, for example, by the meansshown in FIGS. 2 and 3.

It is apparent that when the pork bellies are skinned to remove an outerportion of the skin only, exposing the pebble fat, more hair rootsremain on the pork belly than when the belly is skinned more deeply.Deeper skinning, however, removes more fat and thus results in areduction of yield, yield being defined as the ratio of the weight ofthe belly before skinning to the weight of the belly after curing.

The water pressure at the spray head may be varied between 500 and 900pounds per square inch (p.s.i), depending upon the rate of travel of thebellies past the spray head and the severity of the hair root problem,i.e., the density of the hair roots remaining in the pebble fat. Fornormal hair root conditions, the rate of travel of the mesh belt istypically 30 feet per minute and the pressure is about 700 pounds persquare inch while employing the spray head shown in FIG. 4, which uses33 gallons of water per minute. It is preferred to increase the waterpressure rather than to increase the volume of the water because a highvolume of water tends literally to wash away fat, whereas a fine,low-volume, highpressure spray tends only to remove the hair roots orfollicles. Thus it is seen that a surprising result is achieved inaccordance with the present invention. While one might reasonably expectthat an effert to remove the relatively hard and dense hair follicles,with stubs of air attached, from the soft pebble fat of the pork bellyby means of a spray of water, would result simply in loss of pork fatand leave the hair roots imbedded in the belly, or require the ablatingaway of the fat surrounding the follicles and susbtantial concomitantproduct loss. Contrary to such expectations, however, the removal ofhair roots in accordance with the present invention results in no lossof fat from the pork belly.

The speed at which the mesh belt travels can, of course, be varied tomatch the capacity of the workers and the rate of operation of otherparts of the production line and adjusted according to the severity ofthe hair root problem. Typically, the rate of travel varies from 12 to40 feet per minute. At these rates, a belly requires from 3 to 6 secondsto pass through the spray.

It has been observed that the apparatus of the invention shown in FIG. 1performs most effectively when the pork bellies are moving past thespray head contiguously. No complete explanation is known for this fact,but it is believed that, when the pork bellies are so arranged on themesh belt, they may have a damping effect on the turbulence of the waterspray beneath the hood and thus permit the spray to operate with lessinterference. However, the phenomenon may also be attributable to thepossible, pre-warming efiect produced by the hot water flowing andsplashing forward (in a direction opposite the direction of belt travel)from the spray from one belly to the next.

From the above, it may be seen that substantial savings can be achievedthrough the use of the present invention, both in the increase in yieldand the reduction of the per-unit cost of labor. It is no longernecessary to scrape the pork bellies to remove the hair roots or to skindeeply to take out the hair roots along with the skin, both of whichpreviously necessary operations, reduce the amount of saleable fat.Using the process of the invention, there is essentially no loss ofweight of the skinned belly. Moreover, while it might be expected thatpork bellies contacted with hot water would be more susceptible torancidity, peroxide-value tests show that pork bellies cleaned by theprocess of the invention showed less rancidity than bellies cleaned bymanual scraping. Since the time of contact of the belly with the wateris of such short duration, the rise in temperature of the surface of thebelly is very slight. Normally, the temperature rise is 7 F. in thefirst A inch of the belly only. The belly may be quickly and easilyrecooled to curing temperature.

It is apparent that other variations and modifications may be madewithout departing from the present inven- 6 tion. Accordingly, it shouldbe understood that the forms of the present invention described aboveand shown in the accompanying drawing are illustrative only and notintended to limit the scope of the invention.

What is claimed is:

1. A method of removing hair roots from a skinned pork belly comprisingthe step of spraying the belly with water at a temperature of -140 F.under 500900 p.si. pressure from a spray head at least as wide as thebelly and located a few inches from the belly, and at an angle of 25-45degrees from the perpendicular measured from the surface upon which thebelly rests.

2. The method according to claim 1 wherein the temperature is about F.,the pressure is about 700 p.s.i., and the angle is about 35 degrees.

3. A method of removing hair roots from a skinned pork belly comprisingthe steps of:

conveying the belly on a mesh belt past a spray head at least as wide asthe belly and located a few inches from the belly, and

impinging upon the belly, from the spray head, water at a temperature of130-140 F., under 500900 p.s.i pressure, and at an angle of 25-45degrees from the perpendicular, measured from the surface of the meshbelt and toward the approaching belly.

4. The method according to claim 1 wherein the temperature is 140 F. thepressure is 700 p.s.i., and the angle is about 35 degrees.

5. Apparatus for removing hair roots from a skinned pork bellycomprising:

a mesh belt for conveying the belly;

a spray head disposed a few inches above the belt, at least as wide asthe pork belly, and positioned so as to direct water at an angle of from25-45 degrees from the perpendicular, measured from the surface of thebelt and toward the approaching belly; and

a pump for providing a supply of hot Water to the spray head and underpressure of 500-900 p.s.i. at the spray head.

6. Apparatus according to claim 5 further comprising means forselectively controlling the supply of water.

7. Apparatus according to claim 5 further comprising means for adjustingthe position of the spray head in response to the thickness of the porkbelly, whereby an optimum distance between the spray head and mesh beltis maintained.

References Cited UNITED STATES PATENTS 2,389,404 11/ 1945 Barker l7l 1.12,412,338 12/1946 Jasper l747 2,635,284 4/1953 Hunt 17-1 1.1 2,783,4963/1957 Thomas l747 LUCIE H. LAUDENSLAGER, Primary Examiner U.S. Cl. X.R.l747

